SE543350C2

SE543350C2 - Sensor assembly for a vehicle

Info

Publication number: SE543350C2
Application number: SE1950986A
Authority: SE
Inventors: Dan Zethraeus
Original assignee: Elonroad Ab
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2020-12-08
Also published as: CN114340954A; AU2020339715A1; JP2022546463A; EP4022343A1; WO2021037977A1; SE1950986A1; US20220316923A1

Abstract

The present invention relates to a sensor assembly (100) configured to be mounted on a vehicle (10). The sensor assembly (100) comprises a sensor (20); and a housing (30) housing the sensor (20). The housing (30) comprises an inclined front wall (32) configured to face a main traveling direction (A) of the vehicle (10) and a direction (B) away from the vehicle (20), a vehicle facing wall (34) configured to face towards the vehicle (10), the vehicle facing wall (34) comprising an air inlet (35), and a rear opening (36) forming a viewing opening for the sensor (20), the rear opening (36) being in fluid connection with the air inlet (35) such that air entering the air inlet (35) exits the housing (30) through the rear opening (36).

Description

SENSOR ASSEMBLY FOR A VEHICLE Technical fieldThe present inventive concept relates to a sensor assembly configuredto be mounted on a vehicle.

BackgroundOver the past years, vehicles such as fuel cars and electric cars have developed rapidly. The new generations of vehicles are more equipped withvarious types of sensors and cameras. Such various types of sensors andcameras allow sensing of the vehicle environment. The sensing of the vehicleenvironment becomes extremely important when it comes to autonomouscars.

Nowadays, the use of various types of sensors and cameras onvehicles is limited by their cleanness, as they may e.g. become muddied byadverse weather condition. Therefore, there is a need to protect them againstdirt and keep them clean.

SummaryAn objective of the present inventive concept is to address this need.

Further and alternative objectives may be understood from the following.

According to a first aspect a sensor assembly is provided. The sensorassembly is configured to be mounted on a vehicle, the sensor assemblycomprises a sensor; and a housing housing the sensor. The housingcomprises an inclined front wall configured to face a main traveling directionof the vehicle and a direction away from the vehicle, a vehicle facing wallconfigured to face towards the vehicle, the vehicle facing wall comprises anair inlet, and a rear opening forming a viewing opening for the sensor. Therear opening is in fluid connection with the air inlet such that air entering theair inlet exits the housing through the rear opening.

The inclined front wall of the housing, facing towards the vehicle, facesa wind created by a speed of the vehicle upon driving the vehicle in the maintraveling direction. The inclined front wall guides or reflects at least a portionof the wind to the direction away from the vehicle due to its inclination.Thereby, an air pressure around the rear opening of the hosing becomes lessthan an air pressure of the wind hitting the inclined front wall of the housing.This creates an under-pressure around the rear opening of the hosing and causes the air to be sucked into the housing via the air inlet such that airenters the housing from the air inlet and exits the housing from the rearopening. As a result, the sensor may be protected against dirt such as mudand other particles. Further, the sensor may be protected against humiditysince the air exiting the rear opening may prevent water droplets fromreaching the sensor and hence sticking on the sensor. Thereby, the inventivesensor assembly may provide a simple and a maintenance-free solution forkeeping the sensor clean.

By a sensor is hereby meant a sensing device configured to sense avehicle surrounding. For instance, the sensor may be a camera configured tocapture a video stream of the vehicle surrounding. According to otherexamples, the sensor may comprise one or more of the following: a lidar, aradar, an ultra-sonic sensor, a laser sensor, a passive infrared sensor (PIR), asmoke sensor, a fire sensor, and a temperature sensor. By a housing ishereby meant something that covers or protects the sensor, such as a caseor enclosure. By an air inlet is hereby meant an opening for air to passthrough.

The housing may further comprises a filter configured to filter airentering the air inlet. The air being sucked into the air inlet may hence befiltered by the filter. Thereby, the air exiting the housing through the rearopening and around the sensor may be clean air free from dirt and/ormoisture.

The rear opening of the housing may circumferentially enclose thesensor. Thereby, air may exit via the rear opening circumferentially aroundthe sensor. Hence, a volume of clean air may surround the sensor.

A cross-sectional dimension of the rear opening may at least be twicea cross-sectional dimension of the sensor. Thereby, a volume of clean airexiting the rear opening may be large enough to protect the sensor from dirtyambient air.

By a cross-sectional dimension of the rear opening is hereby meant aminimum size of the rear opening in directions perpendicular to the maintraveling direction of the vehicle. By a cross-sectional dimension of the sensoris hereby meant a maximum size of the sensor in directions perpendicular tothe main traveling direction of the vehicle.

An area of the air inlet may at least be 50% to 80% of the cross-sectional dimension of the rear opening. Hence, it may be secured thatenough air enters the air inlet. 3 By an area of the air inlet is hereby meant a combined area of theopening/openings constituting the air let allowing the air being sucked into thehousing.

The inclined front wall may have an angle in a range from 10° to 40°with respect to the main travelling direction of the vehicle. Thereby, theinclined front wall guides or reflects at least a portion of the air to the directionaway from the vehicle due to its inclination. ln addition, the inclination of theinclined front wall may facilitate the air flow through the housing. Furthermore,the angle range of 10° to 40° may prevent or at least mitigate formation ofvortex in the housing and may facilitate a laminar air flow in the housing.

The air inlet may comprise a plurality of openings. Thereby, the air inletmay provide a support surface for the filter. Also, the air inlet may itself act asa filter by filtering particles larger that a size of openings.

The housing may further comprise at least a mounting bracketpositioned at a distance from the rear opening, the distance preferably beingat least 10% of a cross-sectional dimension of the rear opening. The sensormay hence be mounted at the distance from the rear opening. lt may hencebe safeguarded that the volume of clean air surrounds the sensor keeping thesensor clean. Further, thereby the sensor may be enclosed and protected bythe rear opening. For instance, in the case of the camera, a lens of thecamera may be protected against small rocks and stones from the road thatget knocked up from wheels or other cars.

The housing may further comprise side walls connecting the inclinedfront wall and the vehicle facing wall. The side walls may facilitate formationof a closed channel for the air passing through the housing.

The air inlet may be configured to be connected to an inside of thevehicle such that air entering the housing may be taken from the inside of thevehicle.

A further scope of applicability of the present invention will becomeapparent from the detailed description given below. However, it should beunderstood that the detailed description and specific examples, whileindicating preferred embodiments of the invention, are given by way ofillustration only, since various changes and modifications within the scope ofthe invention will become apparent to those skilled in the art from this detaileddescription.

Hence, it is to be understood that this invention is not limited to theparticular portions and parts of the assembly described as such portions and parts may vary. lt is also to be understood that the terminology used herein isfor purpose of describing particular embodiments only, and is not intended tobe limiting. lt must be noted that, as used in the specification and theappended claim, the articles "a," "an," "the," and "said" are intended to meanthat there are one or more of the elements unless the context clearly dictatesotherwise. Thus, for example, reference to "a sensor" or "the sensor" mayinclude several devices, and the like. Furthermore, the words "comprising",“including”, "containing" and similar wordings does not exclude otherelements or steps.

Brief Description of the Drawinqs The above and other aspects of the present invention will now bedescribed in more detail, with reference to appended drawings showingembodiments of the invention. The figures should not be considered limitingthe invention to the specific embodiment; instead they are used for explainingand understanding the invention.

As illustrated in the figures, the sizes are exaggerated for illustrativepurposes and, thus, are provided to illustrate the general structures ofembodiments of the present invention. Like reference numerals refer to likeelements throughout.

Fig. 1 is a side view of a vehicle comprising a sensor assembly.

Fig. 2 is a perspective view of a sensor assembly configured to bemounted on a vehicle.

Fig. 3 is a top view of the sensor assembly of Fig. 2.

Fig. 4 is a side view of the sensor assembly of Fig 2.

Fig. 5 is a rear view of the sensor assembly of Fig 2.

Detailed descriptionThe present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferredembodiments of the invention are shown. This invention may, however, beembodied in many different forms and should not be construed as limited tothe embodiments set forth herein; rather, these embodiments are provided forthoroughness and completeness, and to fully convey the scope of theinvention to the skilled person. ln connection with Fig.1, a vehicle 10 is shown. The vehicle 10 may, asillustrated in Fig. 1, be a car. However, the vehicle may be any other kind of vehicle, such as a truck, a buss, a tractor, a boat, etc. The vehicle 10 has amain traveling direction A. The main traveling direction A may also be referredto as a forward travelling direction of the vehicle 10. ln connection with Fig. 1 four sensor assemblies 100a, 100b, 100c,100d are mounted on the vehicle 10. lt is understood that a vehicle 10 mayhave fewer or more sensor assemblies mounted thereon. Fig.1 illustrates thata sensor assembly may be mounted at different positions of the vehicle 10.For example, a sensor assembly 100a, 100b may be mounted under thevehicle 10, such as under a middle portion of the vehicle 10 (sensor assembly100a) and/ or under a front portion of the vehicle 10 (sensor assembly 100b).According to another example, the sensor assembly 100c may be mountedon top of the vehicle 10. According to yet another example, the sensorassembly 100d may be mounted on a side of the vehicle 10. ln connection with Fig. 2, a perspective view of sensor assembly 100 isshown. Figs. 3-5 show a top view, a side view and a rear view of the sensorassembly 100 shown in Fig. 2, respectively. The sensor assembly 100comprises a sensor 20 and a housing 30. The sensor 20 may send and/orreceive information from information sending units arranged along a road. Anexample of such sensors is a PIR sensor used for motion detection. Otherexamples of such sensors are lidar, radar, ultra-sonic, temperature, smoke,fire, laser and Infra-Red (IR) sensors. The sensor 20 may be a cameraviewing the vehicle surrounding. The sensor 20 will hereinafter be referred toas a camera 20. However, the sensor 20 is not limited to a camera 20 andmay be any sensor 20 configured on a vehicle 10 which needs to be keptclean. According to other examples, the sensor may comprise one or more ofthe following: a lidar, a radar, an ultra-sonic sensor, and a temperaturesensor.

The camera 20 may provide a view of the vehicle surrounding whenthe vehicle 10 is parked or driving. The camera 20, in the case the sensorassembly 100 is mounted under the vehicle 10, may provide a view of underthe vehicle 10. For instance, the camera 20 may view an animal under thevehicle 10 when the vehicle 10 is parked. The camera may be equipped withan IR lighting. Therefore, the camera 20 may automatically detect even coldobjects moving under the vehicle 10. The camera may further be equippedwith a fire sensor for fire detection. The camera 20 may capture a videostream of the vehicle environment. For instance, if the sensor assembly 100is mounted under the vehicle 20, the camera 20 may provide a video stream of a road where the vehicle 10 is driving on. Data obtained by the camera 20may be used to navigate, control, or drive the vehicle 10.

The housing 30 houses the camera 20. The housing 30 may be formedof a material resistant to temperature variation and humidity. The housingmay be formed of an electromagnetic compatible material. The housing 30may for instance be formed of metal. Examples of such metal are aluminum,steel, and stainless steel.

The housing 30 comprises an inclined front wall 32 facing at least twodirections. The inclined front wall 32 of the housing 30 faces a main travelingdirection A of the vehicle 10. The inclined front wall 32 of the housing 30 alsofaces a direction B away from the vehicle 10. For instance, in the case of thesensor assembly 100 is mounted under the vehicle 10, the inclined front wall32 faces the main traveling direction A of the vehicle and the road. Anotherexample, in the case of the sensor assembly 100c is mounted above thevehicle 10, the inclined front wall 32 faces the main travelling direction A andthe sky. The inclined front wall 32 may have an angle in a range from 10° to40° with respect to the main travelling direction A of the vehicle 10.

The housing 30 further comprises a vehicle facing wall 34 configured toface towards the vehicle 10. The vehicle facing wall 34 may be a flat wall. Thevehicle facing wall 34 may be slightly inclined with an angle in a range of 0° to20°with respect to the main travelling direction of the vehicle 10. The vehiclefacing wall 34 comprises an air inlet 35. The air inlet 35 may comprise oneopening. The air inlet 35 may comprise a plurality of openings. The one ormore openings of the air inlet 35 may have various shapes such asrectangular or circular. The air inlet 35 may be configured to be connected toan inside of the vehicle 10 such that air entering the housing 30 is taken fromthe inside of the vehicle 10.

The housing may further comprise side walls 38 connecting theinclined front wall 32 and the vehicle facing wall 34. The sidewalls 38 mayconnect the inclined front wall 32 and the vehicle facing wall 34 to form aclosed channel for the air passing through the housing 30.

The housing 30 may further comprise a filter 40 configured to filter airentering the air inlet 35. The filter 40 may be arranged in connection with theair inlet 35. The filter 40 may be arranged just above the air inlet 35. The filter40 may be arranged just below the air inlet 35. The air inlet 35 may comprisetwo layers and the filter 40 may be arranged in between the two layers. Thefilter 40 may be composed of fibrous or porous materials to remove particles such as dust and/or moist from the air entering the housing 30. The filter 40may be disposable. The filter 40 may be washable and reusable. The filter 40may have various shapes designed based on the shape of the air inlet 35such as rectangular or circular.

The housing 30 further comprises a rear opening 36 forming a viewingopening for the camera 20. The rear opening 36 of the housing 30 mayenclose the camera 20. The rear opening 36 is in fluid connection with the airinlet 35 such that air entering the air inlet 35 may exit the housing 30 throughthe rear opening 36. A cross-sectional dimension of the rear opening 36 mayat least be twice a cross-sectional dimension of the camera 20. The area ofthe air inlet 35 may be at least 80% of the cross-sectional dimension of therear opening 36. The rear opening 36 may be rectangular. The rear opening36 may be circular or may have other shapes.

A typical size of the housing 30 is 5 to 20cm along the main travelingdirection A, 1 to 7 cm along the direction B away from the vehicle 10, and 3 to10 cm along a direction perpendicular to the directions A and B.

The housing 30 may further comprise a sensor mounting bracket 50a,50b. The sensor mounting bracket 50a, 50b may be arranged inside thehosing 30. The camera 20 may be mounted in the housing 30 by means ofthe sensor mounting bracket 50a, 50b. The sensor mounting bracket 50a, 50bmay be positioned at a distance from the rear opening 36. The distance maypreferably be at least 10% of the cross-sectional dimension of the rearopening 36. The camera 20 may hence be preferably mounted at a distancefrom the rear opening.

The housing 30 may further comprise a vehicle mounting bracket. Thevehicle mounting bracket may be arranged outside the hosing 30. Thehousing 30 may hence be mounted on the vehicle 10 by means of the vehiclemounting bracket.

The person skilled in the art realizes that the present invention by nomeans is limited to the preferred embodiments described above. On thecontrary, many modifications and variations are possible within the scope of the appended claims.

For example, the housing 30 may further comprise a flushingarrangement configured to flush a cleaning liquid onto the sensor 20. Theflushing arrangement may therefore clean the sensor if needed.

Additionally, variations to the disclosed embodiments can beunderstood and effected by the skilled person in practicing the claimedinvention, from a study of the drawings, the disclosure, and the appendedclaims.

Claims

1. A sensor assembly (100) configured to be mounted on a vehicle (10), thesensor assembly (100) comprising:a sensor (20); anda housing (30) housing the sensor (20), the housing (30) comprising:an inclined front wall (32) configured to face a main trave|ingdirection of the vehicle (10) and a direction away from the vehicle (10),a vehicle facing wall (34) configured to face towards the vehicle(10), the vehicle facing wall (34) comprising an air inlet (35), and a rearopening (36) forming a viewing opening for the sensor (20), the rearopening (36) being in fluid connection with the air inlet (35) such thatair entering the air inlet (35) exits the housing (30) through the rearopening (36),wherein the air inlet (35) is confiqured to be connected to aninside of the vehicle (10) such that air enterinq the housinq (30) istaken from the inside of the vehicle (10).

2. The sensor assembly (100) according to claim 1, wherein the housing (30)further comprises a filter (40) configured to filter air entering the air inlet (35).

3. The sensor assembly (100) according to claim 1 or 2, wherein the rearopening (36) of the housing (30) encloses the sensor (20).

4. The sensor assembly (100) according to any one of claims 1-3, wherein across-sectional dimension of the rear opening (36) is at least twice a cross-sectional dimension of the sensor (20).

5. The sensor assembly (100) according to any one of claims 1-4, wherein anarea of the air inlet (35) is at least 50% to 80% of the cross-sectionaldimension of the rear opening (36).

6. The sensor assembly (100) according to any one of claims 1-5, wherein theinclined front wall (32) has an angle in a range from 10° to 40° with respect tothe main travelling direction of the vehicle (10).

7. The sensor assembly (100) according to anyone of claims 1-6, wherein theair inlet (35) comprises a plurality of openings.

8. The sensor assembly (100) according to anyone of claims 1-7, wherein thehousing (30) further comprises at least a mounting bracket (50) positioned ata distance from the rear opening (36), the distance preferably being at least10% of a cross-sectional dimension of the rear opening (36).

9. The sensor assembly (100) according to anyone of claims 1-8, wherein thehousing (30) further comprises side walls (38) connecting the inclined front wall (32) and the vehicle facing wall (34).